1. Field of the Invention
The present invention relates to fuel delivery systems in general, and more particularly to internal combustion engine fuel pumps integrated with fuel filters.
2. Description of the Related Art
There are already known various constructions of fuel delivery systems for internal combustion engines, among them that revealed in the patent publication DE 44 14 281 A1. In this particular configuration, there is provided a fuel-forwarding device, and a disk-shaped filter and a ring-shaped filter are arranged downstream of this fuel-forwarding device. For facilitating the mounting of the fuel-delivery arrangement in the fuel tank, there is provided a common filter housing into which the fuel-forwarding device, the disk-shaped filter and the ring-shaped filter are integrated.
When the fuel-forwarding device and the fuel filter housing are, for instance, connected with one another directly in a synthetic plastic material housing or indirectly via decoupling elements, it can happen that, because synthetic plastic materials are, for the most part, electrically non-conductive, the fuel filter could become electrically charged owing to the fuel flow through the fuel filter housing. This is, of course, a highly undesirable situation to be encountered in fuel-delivery modules. A further disadvantage encountered in connection with housings of synthetic plastic materials is that they are, in most cases, relatively expensive in comparison with housings made of metal.
Accordingly, it is a general object of the present invention to avoid the disadvantages of the prior art.
More particularly, it is an object of the present invention to provide an internal combustion engine fuel-delivery module that does not possess the drawbacks of the known arrangements of this type.
Still another object of the present invention is to devise a fuel-delivery module of the type here under consideration in which the danger of electric charge accumulation is avoided.
It is yet another object of the present invention to design the above module in such a manner that the various components thereof are maintained at the same electric potential.
A concomitant object of the present invention is so to construct the module of the above type as to be relatively simple in construction, inexpensive to manufacture, easy to use, and yet reliable in operation.
In keeping with the above objects and others that will become apparent hereafter, one feature of the present invention resides in an arrangement for forwarding fuel from a fuel tank to an internal combustion engine. This arrangement includes a fuel-forwarding device having a suction side and an elevated pressure side; means including an inlet conduit for connecting the suction side with the fuel tank; means including a fuel-forwarding conduit for forwarding the fuel from the elevated pressure side; a fuel filter housing for accommodating a fuel filter surrounding the fuel-forwarding device; and electrically conductive means for connecting the fuel filter housing with the fuel-forwarding device.
A particular advantage of the arrangement as described so far is that the presence of the electrically conductive means assures that the fuel filter housing and the fuel forwarding device are always maintained at the same electrical potential, so that the possibility of electric discharge between them is eliminated.
Advantageously, the fuel-forwarding device includes a fuel-forwarding device housing; and the fuel filter housing is pressed onto the fuel-forwarding device housing. This feature brings about the advantages of, on the one hand, simple joining of the fuel filter housing and the fuel-forwarding device housing and, on the other hand, the existence of an extensive contact area between the fuel filter housing and the fuel-forwarding device. Other advantages of this approach is that it is not necessary to use any additional connecting elements, and that it is not necessary to manipulate such absent connecting elements.
Another advantageous feature of the present invention is to be found in the fact that the electrically conductive means includes an annular or a cylindrical electrically conductive contact region between the fuel-forwarding device housing and the fuel filter housing. The presence of such a region assures that the fuel-forwarding device housing and the fuel filter housing are always at the same electrical potential at all regions thereof.
This is especially advantageous when there is further provided means for connecting the fuel-forwarding device or the fuel filter housing with a location that is at a predetermined electric potential, especially that of the ground. This assures that, inasmuch as the fuel-forwarding device and the fuel filter housing are electrically connected with one another, they are both maintained at the predetermined electric potential.
According to an advantageous aspect of the present invention, each of the fuel-forwarding device housing and the fuel filter housing is of an electrically conductive material. This electrically conductive material is advantageously a metallic material. An important advantage of this is that such electrically conductive, especially metallic, housings have substantially uniform conductivity throughout, so that the possibility that a charge different from that of the remainders of the housings could accumulate at any region of either one of such housings is, for all intents and purposes, eliminated. In this context, it is especially advantageous when the fuel filter housing includes a lid element. This lid element, which allows easy access to the fuel filter accommodated in the interior of the fuel filter housing, may also be of a metallic material. However, in the alternative, it may even be of a synthetic plastic material.
The arrangement described above may constitute a part or all of a fuel-delivery module for forwarding fuel from a fuel tank to an internal combustion engine, and the latter is advantageously incorporated in a fuel-delivery system for an internal combustion engine.
The novel features that are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.